Stop-motion



A. CRAWFORD.

STOP MOTION.

APPLICATION FILEP MAYII, 1912.

Patented Feb. 24, 1920.

fay/31% A UNITED STATES PATENT oEE o I ALFRED CRA FORD, or NEW BRosWIcn, NEW JERsEY, AssIeNoR TO THE CRAWFORD MANUFACTURING COMPANY, orNEW BRUNSWICK, NEW JERSEY, A coRPoRA'no OF NEW JERSEY.

STOP-MOTION.

Specification of Letters Patent. i Patented Feb, 24, 1920,

Application filed May 17, 1917. Serial No. 169,258.

To all whom it may concern:

Be it known that I, ALFRED CRAWFORD, a citizen of the United States,residing in New Brunswick, Middlesex county, State of New Jersey, haveinvented a Stop-Motion, of which the following is a specification.

This invention relates to knitting machine stop motions, particularly ofthe type described and claimed in a Patent #1,17'2,950, dated Feb. 22,1916, to Frank Crawford, Sn, and has to do more particularly with anovel arrangement of the tension producing means for the fork I orthread engaging member. v

One object of the invention is to so arrange the' connections between aspring and the fork actuating member usually within the head of the stopmotion, that the tension on the fork shall be substantially constantinstead of increasing, as said fork is, moved from its normal to itsthread releasing position.

Another object of the invention is to so construct the thread holdingportion of the fork as to cause it to release the thread with lessangular movement than hitherto, when an abnormal tension is exerted uponsaid thread.

These objects and other advantageous ends I secure as hereinafter setforth,ireference being had to the accompanying drawings, in which,

Figure 1 is a plan of the head of a stop motion with the partsassociated therewith,

showing my invention as applied to the apparatus;

Fig. 2 is a section on the line 2-2, Fig. 1; and

Fig. 3 is an elevation further illustrating one of the features of theinvention.

In the above drawings, 1 represents a portion of the head of a wellknown form of stop motion for a circular knitting machine and this headhas a horizontally projecting arm 2 carrying at its outer end a threadguard 33. Pivoted to said arm is a bell crank lever 1 preferably formedfrom sheet material and having a forked arm 5 extending adjacent theouter portion of the thread guard 3. Adjacent the outer end of j the arm4 there is a branch 6 extending at right angles to its general line andsaid arm 1s pivoted on a screw 7 whose axis 18 inclined to the line ofthe arm 2 at an angle of from sixty to seventy-five degrees more orless. As a result, when the fork is turned on its pivot, its branchedend swings down from what is practically a horizontal position andreleases the thread after but a small angular movement has occurred.

The branched end of said arm extends immediately adjacent the outerportion of the thread guard 3' and the second arm 8 of the fork islikewise branched so as to be capable of engaging the downwardlyinclined' end 9 of a spindle '10 rotatably mounted in a bearing of a lug11 and also having a bearing in the side of the casing 1.

Fixed to this spindle adjacent the casingis a body of wire 12 having anangularlybent arm 13 for the support and guidance of the thread as itpasses from the outer end of the branched 'arm 5 of thefork, downwardlybetween the fingers 14 of an arm 17 and a stationary frame '15.Thislatter device is of the well known form and consists of a wire 16having a sheet metal plate 17 rigidly fixed to it and provided with apair of slots 18 through which the fingers 14 are movable.

The arm 19 projects from a spindle 2Q journaled in a bearing in the sideof the head 1, and extends into the same where it is connected to thewell known apparatus for controlling the stopping of the knittingmachine. The spindle 10 is acted upon by a device within the head 1wherebv through its arm 9, the branched end of the fork is normally heldin the position illustrated, immediately adjacent the thread guard 3 andbeyond which it is prevented from pass ing by a stop 26. The detailarrangement of this portion of the device in the head constitutes one ofthe features of my invention and it includes a hub 21 iournaled on aspindle 22 and having projecting arms 23.

As shown in Figs. 1 and 2, each of these arms is curved and at its outerend has an opening for the reception. of one end of a coil spring :24whose second end is connected to an arm 25 fixed to the spindle 10through a spring coil. The hub 21 with its arms is normally maintainedin a fixed positionon the spindle 22 by a screw 27 which extends intothe head 1 from the outside thereof and is threaded intoa downwardlyprojecting lug on one of said arms;the

arrangement being such that rotation of said screw by turning the hub onthe spindle will vary the tension of the springs '24 within certainpredetermined limits.

As shown in Fig. 3, each of the arms 25 projects from its spindle 10 atan acute angle to the line of its spring 24 so that as it is turned bymovement of the fork arm 5, away from the guard 8, the tension of thespring is but slightly increased. This is due to the fact that the armnormally extends in a line at an angle of about 45 of a line drawn fromthe, spindle through the point at which theaspring 24 is attached to thearm '23, so that as said arm swings toward its dead point position inwhich it would be parallelto said latter line, there is a minimumelongation of said spring. As a result of this construction theresistance to the turning of the fork on its pivot, under the action ofa pull on the thread engagedthereby, remains practically constantinstead .of largely increasing as is the case with the apparatus nowvgenerally in use.

' Moreover by reason of the peculiar form of the branched .arm 5, of thefork, the thread is released after said fork has made but a relativelysmall angular movement as a result of an abnormal tension on the-thread.

It is especially to be noted that the thread receiving end of the forknot only extends in a substantially horizontal line and is so supportedon its pivot as to be swung downwardly in a plane :at an acute angle tothe horizontal, but in addition its extremity is downwardly sloped orpointed so that the thread willslip ofi' withthe utmost ease wheneverthe fork has been swung down through a comparatively small angle as aresult of an abnormal tension.

I claim I 1. The combination in a stop mot-ion for knitting machines, ofa spindle; *a thread engaging member connected to one encl of thespindle; an arm at the opposite end; a second spindle having an armlocated some distance from the arm of the first mentioned spindle; and aspring connecting the two arms, the first mentioned arm being at anacute angle in respect .to line through the center of the first spindleand the point of attachment of the spring at the second arm so that onthe movement of the parts the spring will have a minimum of elongation.

2. The combination a stop motion for knitting machines, of ahead; ahorizontal arm projeoti from the head; a horizontal spindle exteiigingparallel with the arm; an arm on the outer end of the spindle; a threadmember arranged at an acute'angle .to e spindle {and forked at its outerend to engage the thread; an arm on the inner end-of the spindle;- anarm within the head; means tor adjustin said arm; and a springconnecting the ad ustable arm with the arm .on the inner end oi? thespindle, said arm on the spindle being so 10- cated in respect'to theline of the spring that when the spindle is turned the spring willhave alimited amount of movement.

In witness whereof I affix my signature.

ALFRED CRAWFORD.

